Two years ago, Wal-Mart raised its minimum wage for store employees to $9 an hour. Then last year, it unveiled a six-month training program for new employees. Once workers complete the program, called Pathways, their salary is bumped up to $10 an hour.

After reviewing feedback to the program since its launch, the company will now shorten its length to 90 days.

Wal-Mart spokesman Blake Jackson said the company found its associates were able to get through the material of the course — which includes skills tied to a worker's role at the store as well as merchandising, basic economics and "soft" skills — quicker than expected.

Jackson told CNBC that the program has helped improve Walmart's customer service.

Pathways was one element of a $2.7 billion investment Wal-Mart announced in 2015 to improve its training process and boost worker pay. Critics of the program told CNBC earlier this year that they felt the six-month training program was longer than it needed to be.

Wal-Mart is sticking with the annual raise system it put in place last year. This year, workers who were hired on or before Oct. 31, 2016, will get a 2 percent raise on Feb. 18.

Just over half of Wal-Mart's store workers are full-time and an average salary is $13.69 per hour, or about $25,000 a year.